[tex]\displaystyle \\
\texttt{Notatii:} \\
\texttt{n = numarul} \\
\texttt{s = succesorul lui n} \\ \\
\texttt{Calculam succesorul lui n} \\ \\
s = \frac{665+1}{2}= \frac{666}{2}= \boxed{333} \\ \\
\Longrightarrow~~n = 333-1 = \boxed{332} \\ \\
\texttt{Verificare:} \\
333^2 - 332^2 = 110889-110224 = 665 ~~~ \Longrightarrow ~~~ \underline{\underline{Corect} }[/tex]
